Highway Safety Manual (HSM) on the PE Exam

The Highway Safety Manual 2010 (HSM) is introduced for the Spring 2015 PE Exam. The first rule is that there are no accidents anymore, only crashes. The word accident suggests that there is some kind of inevitability to automobile collisions. “Accidents will happen.” The word crash, however, suggests that the unfortunate could have been avoided.

The HSM comes courtesy of the US Department of Transportation and the Transportation Research Board. It’s a resource that provides safety knowledge and tools in a useful form to facilitate improved decision-making. Based on safety performance, HSM serves as a single national resource for quantitative information about crash analysis, and crash evaluation. Its purpose is to apply current knowledge, techniques, and methodologies to estimate future crash frequency and severity. HSM is a means to identify and evaluate options to reduce future crash frequency and severity. It will enable engineers to use limited safety funds cost-effectively.

HSM works through the comparison & evaluation of alternative treatments & design of roadways. Its focus HSM is to provide quantitative information for decision-making. HSM represents a substantial research effort of assembling currently available information and methodologies on measuring, estimating and evaluating roadways in two key ways: crash frequency (number of crashes per year), and crash severity (level of injuries due to crashes)

Many different groups of engineers will rely on HSM that brings new tools and methodologies for planning, programming, project development, construction, operations, and maintenance.
 
HSM uses predictive methodologies to improve and expand the use of crash estimation methods to new and alternative design or conditions in past or future periods. These more statistically rigorous predictive methods will serve to reduce the vulnerability of historical crash-based methods to random variations of crash data. The methods will provide a means to estimate crashes based on geometry, operating characteristics, and traffic volumes.